The Pass of Aglon (or just Aglon), also called the Gorge of Aglon[1], was the pass between Dorthonion and the uplands west of Himring, to the north-east of Beleriand.[2]

It was about six leagues in length, with the western side bordering the Dorthonion Plateau rising in very high steep walls. It was chilly since a bitter wind continuously blew through the pass from the lands to the north.[3]

In F.A.455[4] during the Dagor BragollachOrcs broke through Celegorm and Curufin's fortifications, leaving Maedhros' stronghold the centre for re-grouping of Fëanor's sons. They later took back the Pass.[5] However, after Nirnaeth Arnoediad in 472[6] the Sons of Fëanor were scattered, the Pass of Aglon fell under Morgoth's domination,[7] and it was garrisoned by Orcs.[1] The Pass was never recovered, along with all of the land of northern Beleriand.